If you need to delay video by 3.84 seconds, use a command like this: ffmpeg.exe -i "movie.mp4" -itsoffset 3.84 -i "movie.mp4" -map 1:v -map 0:a -c copy "movie-video-delayed.mp4" However, in the version I have, those settings don't apply to saving the stream. Negative means "move track backwards", as in advance its start time.Positive means "move track forward", as in delay its start time.If the audio and video are out-of-sync when watching the video, VLC makes it easy to adjust - so you can easily discover the exact offset that you need. lv.m4v (for Latvian and just because VLC prefers the. Ideally you won't be doing any encoding or changing encapsulation in this step ( uncheck those), you'll just set the name. Now you select the video only file (otherwise the audio will not be replaced, but will be added to the end of the audio track listing) and the audio language track you want:ĭon't forget to check the "Stream" option. Now you're going to open two files at once. It may save to memory very quickly, but still take another few minutes to actually sync to disc.ĭon't be alarmed if your disc shows something ridiculous like "76MB". Important: The playback bar represents the stream progress. I called mine the same as prior but with video-only just before the extension. You want Video and Keep original video track selected.Ĭhoose the output file. mp4 video without converting the audio?Ĭhoose a compatible container format (probably mp4 if you want it to work on blu-ray players with usb slots, or mkv for hipster stuff) In ffmpeg, how to delay only the audio of a.How to merge audio and video file in ffmpeg.Just as an FYI, this entire process is probably a lot simpler using ffmpeg instead. Add both video and audio that you want (Steps 6-9).The problem lies within libebml, which has been fixed since version 1.3.6, which was released more than a year ago.Ĭopies of VLC packaged by Linux distros using an out-of-date libebml will therefore encounter a crash, at least, with the proof-of-concept. VLC's developers maintain they are not at fault, their software is not vulnerable, and there's nothing to fix: use the latest version of the media player with its latest libraries, and you should be fine. The media player's maker also just recently patched a bunch of flaws in VLC by releasing version 3.0.7.1. In that scenario the software itself is not vulnerable, but rather has privileges associated with it that could allow a malicious plugin to get at sensitive system components. Whether the flaw can be confirmed or not, the clash should serve as a reminder to users and admins that media plugins and players such as VLC can and do contain security vulnerabilities, and should regularly be updated to thwart attempts by hackers to exploit bugs within the code.Įarlier this year, veteran Apple security researcher Patrick Wardle explained how VLC and other legacy applications could be used by attackers as entry points for attackers looking to get around newer macOS security protections.
El Reg has asked VLC developers at VideoLan for additional comment on the matter, and will update the story when we hear back. MP4 was generated as a result of an automated bug-hunting fuzzer running against VLC. So there is confusion over what Kempf meant by "does not crash" – because it surely does crash – and whether by "the bug is not reproducible," he meant remote-code execution is impossible or possible. MP4 in VLC version 3.0.7 Vetinari (3.0.7-0-g86cee31099) on Linux, the player crashed with a segmentation fault. When The Register tried playing the proof-of-concept. It's 2019 and you can still pwn an iPhone with a website: Apple patches up iOS, Mac bugs in July security hole dump READ MORE